Marking compositions, including various drawing and writing compositions are known in the art, such as crayon compositions, color pencil compositions and the like. These marking compositions, and in particular crayons compositions, are generally prepared by mixing together one or more petroleum based waxes such as water insoluble paraffin, carnauba wax, hydrocarbon waxes and the like, with, at times, fatty acids, in a molten state in a suitable combination in accordance with the quality of crayon required, adding talc to the molten mixture as a structuring agent, adding a pigment to the molten mixture as a colorant, pouring the resulting composition into a specified mold and solidifying the composition by cooling.
While these crayons are functional, petroleum-based waxes are derived from non-renewable sources. Crayon manufacturers therefore, have sought to use ingredients that are derived from renewable sources, such as natural oils, thereby lessening their reliance on non-renewable oil. This is especially important since waxes are not a major byproduct of oil production, and at times they are in short supply. In addition, by using renewable sources crayon manufacturers appeal to customers who desire environmentally friendly products.
There are fundamental differences in the inherent properties of the renewable, natural oil based saturated triglycerides when they are compared to the petroleum based straight chain aliphatic hydrocarbons that make up paraffin based crayons. Triglycerides exhibit well-documented polymorphic behavior whereas the aliphatic hydrocarbons of paraffin do not. “Polymorphism” means there are multiple crystal forms of the material that can (co)exist. In general, under rapid cooling, less stable lower melting and less molecularly dense crystals form initially, but given time and freeze-thaw cycles, the mobility of the molecules allow their rearrangement to higher melting, more stable and more molecularly dense crystal forms. This rearrangement can lead to the problems of cracking and blooming (i.e., “fat blooming”) in a marking composition produced from natural oil, and in particular, a crayon composition produced from a natural oil.
Fat blooming of a crayon composition produced from natural oils, as a consequence, can result in a loss of sales and increased handling and production costs to the manufacturer. As a result, there is continuing interest in developing crayon compositions substantially free of fat bloom from natural oils and natural oil derivatives, and in some embodiments, to develop a crayon composition substantially free of fat bloom from natural oils and natural oil derivatives. By the use of natural oil based triglycerides, a cost reduction can be obtained over the use of paraffin and fatty acids, such as stearic acid, in the formation of the crayon composition.